1. Field of the Invention
This invention relates generally to improvements in propeller systems, and more particularly, it pertains to a new method and system for developing a propulsive force in a gaseous or liquid fluid that can be used for propulsion or sustaining aircraft, marine vessels, and land vehicles, such for example, as snowmobiles, etc. Numerous other applications can be derived from the use of this invention, for example in designing apparatus for moving gaseous or liquid fluids such as fans, pumps. etc.
2. Description of the Prior Art
Historically, various propeller and paddling systems have been developed for propulsion of different types of vehicles by movement of water or air in opposite direction to the movement of the vehicle. Although, at the present time, screw type propellers are the most common form of marine and aircraft propulsion, they have a number of disadvantages. Because the propeller blades are oriented at certain angles to the direction of the rotation, a lot of energy is being lost to friction with air or water, wake forming, vortices, cavitation, etc. The screw propellers are also relatively noisy, which may be undesirable in many situations, such as for submarines, for fishing or pleasure boats, etc.
Many improvements of the screw propellers have been suggested throughout the years. Numerous patents and researches have been devoted to development of propeller systems wherein the propeller blades are pivoted simultaneously with rotation of the driving shaft and to the problem of optimizing such cyclic variations of the orientation of individual blades. Some of such systems utilize rotation of propeller blades or paddles not only around the axis of the driving shaft but also around complementary axes of rotation for more effective exertion of propulsive force. The basic concept presented in these systems is that the usable propulsive force is developed as a result of rotating the blades around two axes of rotation with variable orientation of the rotated blades relative to the driving shaft.
Propulsion apparatus are known (U.S. Pat. No. 1,284,282 to Fitzpatrick, U.S. Pat. No. 1,450,454 to Roney, U.S. Pat. No. 1,667,140 to Clark, U.S. Pat. No. 1,923,249 to Abram) wherein blades of feathering type extend radially from the driving shaft and are rotated around radial axes simultaneously with rotation of the driving shaft. In the paddling position, the blades are held in a plane parallel to the axis of the driving shaft and in the feathering position, the blades are held in a plane perpendicular to the axis of the driving shaft. A serious drawback of such systems is that, in the process of changing from one position to the other, the blades have to be rotated 90 degrees around their longitudinal axes with a considerable resistance of the fluid and low paddling and propulsion efficiency during such rotation. That is why such systems have low propulsion efficiency in comparison with screw type propellers.
There are also known propulsion apparatus wherein the propeller blades are oriented and rotated in the planes parallel to the driving shaft (U.S. Pat. No. 3,270,820 to Frazier, British patent No. 217,223 to Pensovecchio). Although having advantages in respect to the propellers with feathering blades, such apparatus with only two blades mounted in a plane perpendicular to the propeller shaft also have low efficiency and irregular power consumption. Different combinations of such propulsion apparatus are cumbersome and the mechanisms employed to effect their operations are far too complicated to render them practical. For these reasons, a limited success has been obtained by such type of apparatus.
The invention seeks to overcome the deficiencies of known propulsion systems and to benefit from the advantages that may be expected from the new method and system.
The object of the invention is to provide a reliable propulsion system for marine vessels, aircraft and land vehicles with improved propulsion and energy efficiency.
The invention is based on my discovery that an effective propulsive force in a liquid or gaseous fluid can be developed by rotating a driving shaft with four blades which are simultaneously rotated around two intercrossed axes which are perpendicular to each other in a plane perpendicular to the axis of the driving shaft. Each blade is oriented so that it is always held in a plane generally perpendicular to the axis around which it is rotated. The blades and the driving shafts are interconnected so when two parallel blades, which are rotated around one of the intercrossed axis, are oriented in the same direction parallel to the axis which is perpendicular to the driving shaft, the other two parallel blades, which are rotated around the other of the intercrossed axis, are oriented in opposite directions parallel to the axis of the driving shaft. Each two adjacent blades mounted in perpendicular planes are rotated in different directions (clockwise and counterclockwise). It was discovered that it is possible to rotate four such blades around perpendicular intercrossed axes without interfering with each other simultaneously around the driving shaft and the perpendicular intercrossed axes with the same speed. During such double rotations, the radial extensions of the blades relative to the driving shaft are changing as a function of the angle of rotation. As a result, both sides of the blades are being used consecutively as paddling surfaces and the speed of paddling motion of the blades is changing during each stroke, resembling a fishtail or frog-leg action of the aquatic nature. Preferably, the blades have airfoil sections.
In preferred embodiments of the invention, the blades are constrained by the planetary gear engagements to rotate with the same speed around the axis of the driving shaft and around the intercrossed axes of the radial shafts mounted in rotated gear-boxes. Each gear-box comprises four radial shafts on which planet angle mitre gears and blades are mounted. The sun gears of the planetary engagements are mounted coaxially to the driving shafts.
In addition, simultaneously with the paddling process, the rotated blades can work as a double screw propeller if they are mounted with angles of incidence in the planes of rotation around the radial axes. Because the orientations of the blades are constantly changed during the rotation of the driving shaft, the angles of incidence of them must be variable. For this purpose, the blades may be mounted on the radial shafts with ability to swing around the axes perpendicular to these shafts. They can be swung by circular cams mounted coaxially with the radial shafts.
For developing a unidirectional propulsive force, the propulsion system may include two or more parallel driving shafts rotated in opposite directions. It is possible to mount the driving shafts in vertical or horizontal positions in a close proximity to each other and/or to a driven vehicle by the sides where the rotated blades are parallel to the driving shaft.